A necessity for providing means of subsistence for the Eskimos and other natives of Alaska is hereby declared to exist. It is also declared to be the policy of Congress, and the purpose of this subchapter, to establish and maintain for the said natives of Alaska a self-sustaining economy by acquiring and organizing for and on behalf of said natives a reindeer industry or business, by encouraging and developing native activity and responsibility in all branches of the said industry or business, and by preserving the native character of the said industry or business thus established.